jdbc连接mysql数据库简单代码

import com.mysql.jdbc.Driver;

import java.sql.*;


public class ConDB {
    //设置本地MySQL数据库连接字符串
    private final static String URL="jdbc:mysql:///approve_demo?user=root&password=admin";
    //执行查询操作的方法
    public ResultSet queryMysqlDB(String sqlQuery){
        ResultSet resultSet;
        try {
            new Driver();
            Connection connection = DriverManager.getConnection(URL);
            PreparedStatement statement = connection.prepareStatement(sqlQuery);
            resultSet = statement.executeQuery();
            return resultSet;
        } catch (SQLException e) {
            e.printStackTrace();
            return null;
        }
    }
    //执行插入操作的方法
    public void insertMysqlDB(String sqlInsert,String sqlQuery){
        ResultSet resultSet;
        try {
            new Driver();
            Connection connection = DriverManager.getConnection(URL);
            PreparedStatement statement = connection.prepareStatement(sqlQuery);
            resultSet = statement.executeQuery();
            if (!resultSet.next()) {
                statement=connection.prepareStatement(sqlInsert);
                statement.executeUpdate();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    //执行更新操作的方法
    public int updateMysqlDB(String sqlUpdate){
        int check = 0;
        try {
            new Driver();
            Connection connection = DriverManager.getConnection(URL);
            PreparedStatement statement = connection.prepareStatement(sqlUpdate);
            check=statement.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return check;
    }
}